[GRASS-user] Seg fault with i.group in script

[Ned Horning]

Hamish,

Thanks for the debugging tips - they are helpful. It looks like it was a 
problem with my variable names. I've been getting confused about when to 
prefix the variable name with a "$". Dropping the "$" from the raster 
names in i.group seems to have fixed the problem.

I have i.group working but now I realize there is another problem I need 
to solve before the script will work. Slowly learning...

Ned

Hamish wrote:
> try running with the --verbose flag turned on.
> also `g.gisenv set="DEBUG=5"`  (set back to 0 to turn them off)
>
> can you change the top line of the shell script to be
> #!/bin/sh -x
>
> then you can follow the exact expansion of the shell variables
> from among the debug noise.
>
> probably python/bourne shell makes no difference; the imagary
> library is not as robust as the raster one.
>
> perhaps the band name is very long? only recently have a lot
> of the i.* modules been updated to deal with that. Looks like
> that was a year ago so should be ok in 6.4.0rc5.
>
>
> make sure there are no @mapset in the map names.
>
> ...?
>
>
> Hamish
>
>
>
>
> Ned wrote:
>   
>> Hi - I have a script that uses
>> i.group to group 6 bands but when it runs I get a
>> Segmentation fault. If I run the same i.group command
>> (without "$") in the terminal it works just fine. This is
>> the i.group command I am using in the script:
>>
>> i.group group=allBands subgroup=allBandSub
>> input=$band1_corrected,$band2_corrected,$band3_corrected,
>> $band4_corrected,$band5_corrected,$band6_corrected
>>
>> Is there anything obviously wrong? I am running this on
>> Ubuntu using GRASS 6.4.0 RC5
>>
>> Would it make a difference if I converted the script to
>> Python? I want to start learning how to write Python scripts
>> and perhaps this is the time to learn.
>>     
>
>
>
>       
>
>